1. Field of Invention
This invention relates to a package of a continuous strip or sheet of pliable material and to a method for forming a package of a continuous strip or sheet of pliable material.
2. Description of Related Art
Previously packages of a continuous strip of material have been formed using a technique known as xe2x80x9cfestooningxe2x80x9d in which the strip is folded back and forth to lay a series of strip portions back and forth with each portion being folded relative to the next about a line transverse to the strip. The technique of festooning has been available for many years and is used in packaging many different types of material but particularly material of a fibrous nature such as fabric, non-woven strips and the like. In this technique, the strip is conventionally guided into a receptacle such as a cardboard box while a first reciprocating movement causes portions of the strip to be laid across the receptacle and folded back and forth and a second reciprocating movement causes the positions of the portions to be traversed relative to the receptacle transversely to the portions. Normally the receptacle comprises a rigid rectangular container at least partly of cardboard having a base and four upstanding sides.
The purpose of the festooning method is for packaging the strip for supply to a machine using the strip. Some users prefer the festooned package relative to a wound package of this type of material. The festooned package contains a much greater length of material than a spirally wound pad. The festooned package can simply be located adjacent the machine without the necessity for any unwinding or support stand. In addition, both the leading end and the tail end of the package are available at the top of the package so that a series of the packages can be connected lead to tail to act as an extended supply. Yet further, since the material is simply laid into the package, there is less problem with tension control in the material as it is withdrawn from the package, in comparison with larger traverse wound packages where tension control of large packages can be a problem due to the inertia of the package thus requiring a driven unwind stand as well as material handling equipment for moving the large rolls. There is therefore no need when festooned packages are used for a complex unwind stand which takes up more space than may be available and involves significant cost.
Festooned packages are formed in a stiff container or box to properly enclose and contain the material and within which the material is stored during transportation for maintaining the material against compression and distortion due to the transfer of loads from surrounding packages. The cardboard container thus provides support for other similar stacked containers and prevents the transfer of loads from the stacked packages from causing excessive compression of packages at the bottom of a layer. The cardboard containers and the package structures used in the conventional arrangement however have a number of problems.
Firstly the container must be either recycled with the necessity of shipping the cardboard containers in the return direction to the supplier from the end user or they must be discarded, both at considerable expense.
Secondly the cardboard containers simply receive the material without significant compression so that there is wastage of space within the container due to the packaging of air with the material. In addition the conventional package structure does not minimize the amount of air spaces formed in the structure. The transportation costs of the material therefore are significantly increased by the large volume of the material which provides a density which is significantly below the optimum for most efficient transport.
Thirdly the presence of the essential box during formation of the structure provides a restriction to the proper control of the strip as it is laid down since the sides of the box provide limitations to the position and movement of the guide member controlling the strip.
Fourthly it has been noted that the sides of the box which are parallel to the strips as they are laid down do not closely confine the sides of the package structure with the significant danger that the strips can fall down between the edge of the package and the box side.
In addition, the conventional technique for forming the package in which each of the strips slit from a web of supply material is individually packaged at a separate festooning station is slow and requires a large amount of floor space for the large number of stations. Also the large area covered by the stations causes a significant distance to be traveled by the strip from the slitting station to the festooning station with the potential for strip tension problems and damage to the strip.
There remains therefore a significant requirement for a package of this general type but the techniques presently available are unsatisfactory for the above reasons leaving opportunity for an improved package structure.
It is one object of the present invention, therefore, to provide an improved package structure and a method of packaging a strip of material in which the stability of the package can be improved and the economics of transportation and storage of the package can be improved.
According to one aspect of the invention there is provided a package of a strip comprising:
at least one stack of a strip;
the strip having a first side edge, a second side edge, a first surface and a second surface;
in said at least one stack the strip being repeatedly folded back and forth so that the stack contains a plurality of folded overlying strip portions of the strip, with each strip portion being folded relative to one next adjacent strip portion about a first fold line transverse to the strip and relative to a second next adjacent strip portion about a second fold line transverse to the strip and spaced from the first fold line;
the strip portions forming a plurality of first fold lines at one end of the at least one stack and a plurality of second fold lines at an opposed end of the at least one stack;
the strip portions being arranged such that the first surface of each strip portion lies directly in contact with the first surface of one next adjacent strip portion and such that the second surface of each strip portion lies directly in contact with the second surface of the other next adjacent strip portion;
the strip portions being arranged with the first side edges thereof lying directly on top of and aligned with the first side edges of others of the strip portions of the stack and with the second side edges thereof lying directly on top of and aligned with the second side edges of others of the strip portions;
the strip portions being arranged with the first and second surfaces thereof generally parallel to a top surface and bottom surface of the at least one stack with the strip continuous through the stack between a bottom strip portion and a top strip portion;
the at least one stack being substantially upright and having a splice tail portion of the strip extending from the bottom strip portion and extending beyond an end of the at least one stack so as to be accessible for splicing;
the entire top surface and the entire bottom surface of the at least one stack being under compression from an external force in a direction at right angles to the top surface and the bottom surface of the at least one stack; and
the at least one stack being engaged by a packaging material which maintains the compression.
Preferably the packaging material comprises a closed bag surrounding the package from which air has been withdrawn and which is sealed against ingress of air.
Preferably the compression applied by said compression force is sufficient to reduce the thickness of each strip portion of said at least one stack.
Preferably the strip is fibrous such the each strip portion is compressed by expelling air from interstices between the fibers.
Preferably the packaging material comprises two rigid header plates, each engaging a respective one of a top surface and a bottom surface of the package and each applying pressure thereto for maintaining the compression.
Preferably the splice tail portion extends along the end of the stack and is folded about at least one fold line generally transverse to its length to define two folded strip portions.
Preferably the method includes providing a slip sheet between the two folded strip portions.
Preferably there is provided a spacer sheet between the fold lines at an end of the stack and the splice tail portion.
Preferably the package is maintained compressed in a direction at right angles to the strip portions of the at least one stack by an amount sufficient to form a rigid free standing package structure without rigid container walls.
Preferably there is provided a container member defining at least one pocket for containing and supporting the splice tail portion.
Preferably there is a plurality of the stacks arranged side by side without intervening rigid container walls and wherein there is provided for each stack a respective splice tail portion extending beyond an end of the respective stack and wherein there is provided a container member defining at least one pocket for containing and supporting the splice tail portions.
Preferably the container member includes a plurality of pockets each for receiving a respective one of the splice tail portions.
Preferably the container member comprises a spacer sheet between the fold lines at an end of the stack and the splice tail portions and at least one pocket carried on the spacer sheet for containing the splice tail portions.
Preferably each splice tail portion is connected by a splice to a top strip portion of a next adjacent stack to define a splice connection portion extending from the bottom strip portion of one stack to the top strip portion of the next adjacent stack and wherein the stacks are compressed such that a length of the splice connection portion is longer than the height of the compressed stacks and wherein an excess length portion of each splice connecting portions is inserted into the at least one pocket.
Preferably the at least one pocket comprises a sleeve mounted on an outer surface of the spacer sheet defining an open top and an open bottom.
Preferably each splice tail portion is connected by a splice to a top strip portion of a next adjacent stack to define a splice connection portion extending from the bottom strip portion of one stack to the top strip portion of the next adjacent stack and wherein the stacks are compressed such that a length of each splice connection portion is longer than the height of the compressed stacks and wherein a first excess length portion of each splice connecting portion is inserted into the open top of a respective one of the pockets and a second excess length portion of each splice connecting portion is inserted into the open bottom of a respective one of the pockets.
According to a second aspect of the invention there is provided a method of forming a package of a strip comprising:
providing at least one stack of a strip;
the strip having a first side edge, a second side edge, a first surface and a second surface;
in said at least one stack folding the strip repeatedly back and forth so that the stack contains a plurality of folded overlying strip portions of the strip, with each strip portion being folded relative to one next adjacent strip portion about a first fold line transverse to the strip and relative to a second next adjacent strip portion about a second fold line transverse to the strip and spaced from the first fold line;
the strip portions forming a plurality of first fold lines at one end of the at least one stack and a plurality of second fold lines at an opposed end of the at least one stack;
arranging the strip portions such that the first surface of each strip portion lies directly in contact with the first surface of one next adjacent strip portion and such that the second surface of each strip portion lies directly in contact with the second surface of the other next adjacent strip portion;
arranging the strip portions with the first side edges thereof lying directly on top of and aligned with the first side edges of others of the strip portions of the stack and with the second side edges thereof lying directly on top of and aligned with the second side edges of others of the strip portions;
arranging the strip portions with the first and second surfaces thereof generally parallel to a top surface and bottom surface of the at least one stack with the strip continuous through the stack between a bottom strip portion and a top strip portion;
arranging the at least one stack substantially upright and having a splice tail portion of the strip extending from the bottom strip portion and extending beyond an end of the at least one stack so as to be accessible for splicing;
compressing the entire top surface and the entire bottom surface of the at least one stack from an external force in a direction at right angles to the top surface and the bottom surface of the at least one stack; and
engaging the at least one stack by a packaging material which maintains the compression.